When Jack Dorsey isn't busy speaking at conferences about the growing influence of the popular micro-blogging website Twitter, he's hocking his latest venture--Square.

Square is an electronic payment service that lets people charge credit cards from their phones. It requires a small attachment (shaped like a square, of course), and an internet connection.

Today, the company announced one of its biggest successes yet: The New York City Taxi and Limousine Commission has approved a proposal to deploy 30 taxicabs with Square.

I can't wait to get back to NYC to use @Square in taxis! Favorite feature: swipe your card anytime during the trip instead of at the end, tweeted Jack Dorsey.

Verifone Systems Inc and Creative Mobile Technologies LLC hold contracts to power credit card payments in more than 13,000 cabs across New York City according to an AllThingsD report. The companies have installed Taxi TVs, which shows media provided by ABC and NBC while also processing credit card information.

At this moment, it's not clear on whether credit card transaction fees will be lower with Square devices. Davis Yassky, the chairman of the NYCTLC, told the New York Times that the installation of Square with iPads could open up opportunities for a variety of content and computer applications.

Other cities have already installed Square devices in taxi cabs such as Baltimore, San Francisco, Orlando, Seattle and Portland.

A Square representative said the taxis will use a version of Square's existing software, thought it will be slightly modified to work best with taxis according to NBC.